Siren



May 18 1926.

NEI-3B, JR

SIREN Filed Sept. 1, 1925 Patented May 18, 1926.

UNITED STATES 1,585,219 PATENT orner..l

DUDLEY R, WEBB, JR., 0F PHILADELIJHIA, PENNSYLVANIA, ASSIGNOR TO FEDEAL ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SIREN.

Application led September 1, 1925.

My invention relates to sirens, and the object of the invention is to provide means by which the sound may be sont in various directions from a siren which is stationary. Sirens of course are lor various purposes, one ot which is for giving alarm to a wide territory. For example, sirens are commonly used in small communities for sounding an alarm of tire. These sirens are mounted in lixed position, usually at considerable elevation, and it has been found that in some localities, especially where the country is hilly, the sound is cut oit prematurely, in some directions more than in another. rIhe purpose oit this invention is to remedy this detect and provid-e means tor varying the volume in dilerent directions as local conditions may require. A contributory object is to accomplish the purpose without complicating the apparatus to any appreciable degree. The type ot' siren almost universally employed has a rotor which revolves about a horizontal aXis, and in accomplishing my purpose I have taken this into account and have provided a sound-directing element which itself is adjustable angularly about an axis coincident with the axis of the rotor. Another object is to utilize the directional control mechanism for protecting the sound producing parts from the weather.

I accomplish my objects by the mechanism illustrated in the accompanying drawing in which- Figure 1 is an assembly view in side elevation, partly in axial section, showing the siren and sound directing elements.

Figure 2 is an end view looking toward the right in Figure 1.

Figure 3 is an end view looking toward the left in Figure 1.

Like numerals denote like parts throughout the several views.

In the form shown in the drawings there is a main housing 1 standing on a base 2 and enclosing the motor 3. The motor shaft 4 is supported within bearings 6 in the housing 1. It is 'extended at the ends for attachment to the hubs of the siren rotors 8. Each rotor rotates within a stator 10 which is concentric with it. The rotor and stator are slotted in the usual manner to produce sound when the rotor revolves. The parts thus far described are'ot ordinary construction.

Each stator 10 is extended horizontally at the end, thus forming a hollow cylinder 12 Serial No. 53,848.

through which the stream of air enters the rotor. Mounted partly upon this cylindrical extension and partly upon the casing 1 is a hood 14 which is intimately concerned with the invention. The hood flares outward and at the inner 'end has a flange 16' which is cylindrical and fits over the cylindrical end of the casing 1. This flange has annular slots 18 for accommodating studs 2O which radiate at intervals from the housing 1 at the ends thereof. These studs are threaded at the outer ends where they are provided with wing nuts 22 by which the hoods may be secured in any position to which they have been angularly adjusted.

Near the outer end of each hood are radial arms 24; fastened at the outer end to the inside of the hood and at the inner end to a ring 26 which tits slidingly upon the eX- tension 12. As a result of this construction, when the wing nuts 22 are backed off the hoods may be adjusted angularly to any desired position.

The hoods have an opening in the side, that is, they have a sector removed through which the sound produced by the siren may issue readily. rIhe cut-away sector may vary in size, but experience teaches that an opening ot' approximately 90 degrees is appropriate. While not essential, it is desirable that a lip or flange 28 be formed at one margin of the opening of each hood for the purpose of better controlling the direction and conserving the volume of sound.

In practice, it is first determined by tests or otherwise what direction it is desired to have the major portion of the volume of sound pursue. Practically speaking, it is never desired to have the sound travel upward, as it would be merely dissipated. Therefore the opening in the side of the hood is almost always adjusted partially downward, that is, below the horizontal. In Figure 2 I have shown the hood at the left of the siren with its opening straight down and in Figure 3 I have shown the hood at the right end of the siren extending downward toward the right. In the first named adjustment the sound will be directed partly out through the end of the hood and partly in a downward direction. In the last named adjustment the sound will travel horizontally outward with a considerable portion traveling obliquely downward and toward the side. It has been found that by properly adjusting these hoods the travel of sound may be controlled to a remarkable degree. rhe sound from one rotor may be thrown horizontally in one direction and from the other rotor in the opposite directionC and many combinations may loe produc-erh thus making it possible to direct the sound either to points Where it is mostlyv required or toward points Where trees, hills or other ohstructions out down the volume and hence an increased proportion is necessary for coml'iensation. Thus as a result ot my invention it is possible to control quite accurately the distrihuticrA ot the sound and it vill loe observed that this distribution is controlled lijf hoods which rotale about the saine axis as the motor and are or Very simple construction.

The hoods do not add particularly to the space required hy the apparatus, and theyY perform the additional function ot protecting` from the Weather the sound producing' Darts ot' the machine. Thus the hoods coinbine the effect of protections for keepingl the apparatus 1n goed working condition and 2 conservation and control ot' the sound which the apparatus produces.

Having thus described my invention what l claim new and desire to secure by Letters Patent is:

l. A siren having a stator and a rotor. and a hood surrounding a portion onlyv of the rotor, `the hood bein@` rotatably adjustable about a horizontal aus for controlling the direction of the sound.

2. siren haring a stator and rotor haring a common horizontal axis, a 'flaring' hood circum'lerentially arranged around the rotor and covering' the upper portion thereof 'for inotecting it trein the Weather, the hood reing; open at the end and also at the lo portion. and means for annularlj,Y adjusting the hood about the rotor artis tor contr ,\llingthe direction ot the sound.

In Witness Whereo' l have hereunto su scribed my name.

DUDLEY WEBB, Ju. 

